weekday {clock}  R Documentation 
A weekday
is a simple type that represents a day of the week.
The most interesting thing about the weekday type is that it implements circular arithmetic, which makes determining the "next Monday" or "previous Tuesday" from a systime or naivetime easy to compute. See the examples.
weekday(code = integer(), ..., encoding = "western")
code 
Integer codes between 
... 
These dots are for future extensions and must be empty. 
encoding 
One of:

A weekday vector.
x < as_naive_time(year_month_day(2019, 01, 05))
# This is a Saturday!
as_weekday(x)
# Adjust to the next Wednesday
wednesday < weekday(clock_weekdays$wednesday)
# This returns the number of days until the next Wednesday using
# circular arithmetic
# "Wednesday  Saturday = 4 days until next Wednesday"
wednesday  as_weekday(x)
# Advance to the next Wednesday
x_next_wednesday < x + (wednesday  as_weekday(x))
as_weekday(x_next_wednesday)
# What about the previous Tuesday?
tuesday < weekday(clock_weekdays$tuesday)
x  (as_weekday(x)  tuesday)
# What about the next Saturday?
# With an additional condition that if today is a Saturday,
# then advance to the next one.
saturday < weekday(clock_weekdays$saturday)
x + 1L + (saturday  as_weekday(x + 1L))
# You can supply an ISO coding for `code` as well, where 1 == Monday.
weekday(1:7, encoding = "western")
weekday(1:7, encoding = "iso")